Halogenation of anthraquinone derivatives



i 'Q time or FREDERICK "WILLIAM ATACK, 0L IVIANCHESTER, ENGLAND, AND GEGRGE ROBERTSON.

0F COUPER ANG'Ufi, SCOTLAND.

Ji-ZALQGENATION 0F Alll'TZ-ERAQUINONE DERIVATIVES.

Leitllfllgti 1W0 Drawing. Application filed June 3,

To all whom it mag concern:

Be it known that we, FREDERICK lVILLiAM Amen and Guonon Ronrn'rsoN, subjects of the King of Great Britain, residing in Mair chester, in the county of Lancaster, England, and Cooper Angus, Scotland, respectively, hare invented certain new and useful improvements in the Halogeuation of Anthriu quinone Derivatives, of which the lolli'iwing is a specification.

The present invention relates to improvements in the helogenation of anthraquinonc derivatives.

We have discovered that if chlorination of Lhydroxy-anthraquinone (for example) is performed in presence of a hot aromatic liquid and a reagent capable of neutralizing the hydrochloric acid produced, it is possible to obtain excellent yields of .l-chlor4hydro: :y enthraquinone, whereas in the absence of such a reagent, unsatisfactory results are obtained, the end product formed not being of the same degree of purity. The addition of a neutralizing agent accelerates the completion of the chlorination, and further enables the progress of the reaction to be better ascertained. The addition of the neutralizing agent is therefore a great technical zl'dvantage.

The invention also extends to other authraquinone derivatives especially acylaminoanthraquinones. Unsubstituted amino-anthraquinones are not included since they can be readily chlorinated in cold liquids.

It is desirable to avoid side reactions 6. between thehalogenatiug agent, the aromatic liquid and the neutralizing agent, and it is therefore best to use a mild alkaline reagent, rather than caustic elkalis. An inert or ganic liquid is preferred to liquids such as glacial acetic acid, which although suitable in some respects, reacts with chlorin when heated,

Chlorination may conveniently be per formed by direct action of free chlorin iu nitrobenzene suspension, and iodin may be edded as a carrier if desired.

, Ewcmiplc 1.

22.4 parts by 'weight l-hydroxyanthraquinone, 48 parts by weight nitro-benzene, 6 parts by weight anhydrous sodium can bonate and 0.5 parts by weight of iodin were heated together and chlorin passed in until the necessary increase in weight has oc- Specification of Letters Patent.

Patented Dec. 27, 1921.

1921. Serial No. 474,756.

curred. After allowing to cool, the product was filtered oii', washed with alcohol, and dried. (in recrystallization from glacial acetic acid 1-chlorl-hydroxyanthraquinone of melting point 190-1Q2 C. (corr) was obtained.

E'auzmpl L.

15 parts by weight of finely powdered tered from the aqueous liquor; the product has a Mi. P. 210-212 C.

Eavmnpie 3.

16 parts by weight of 1.benzoylamin-anthraquinone, 120 parts by weight of nitrobenzene, 3 parts by weight of sodium carbonate and part by weight of iodin are treated with chlorin gas at 120125 C. until the necessar 1 increase in weight for monochlorination has occurred. The product crystallizes out on. cooling and has M. P. 253 255 C.

Example 5.

48 parts by weight of alizerin, 28 parts by weight sodium carbonate, 1 part by weight iodin, u. d 480 parts by weight nitrobenzene are heated to a temperature of 100l10 C. and chlorin passed in untll an increase in weight corresponding to the formatlon of a diehlor derivative 1S obtelned. On cooling the product crystallizes out and 1s filtered, freed from nitrobenzene and dried. The

product contains 21.9% C1 (required for dichloralizarin 22.5%) and has a melting point of 24a-2 l6 C.

Example 6. 12 parts by weight of anthrarufin, 60 parts by Wei ht of nitrobenzene, 3 parts by weight of sod ium carbonate, and 0.25 parts by weight of iodin. are heated together to a temperature of fill-120 C. and chlorin introduced until the necessary increase in weight for the formation of a monochlor derivative has occurred. On cooling the product crystallizes out and is f ltered. washed and dried. The substance has all the properties ascribed to monchloranthrarufin in G. P. 167,743.

Example '7.

2-1- parts by weight of anthrarufin, 120 parts by weight of nitrobenzene. 12 parts by weight of sodium carbonate. 1 part by weight of iodin are heated together in a stream of chlorin until the required increase in weight for the formation of a dichlor derivative has occurred. After allowingto cool, the productis isolated in the usual manner. The yield is almost quantitative. The reactions or the compound are similar to those described for dichlor-anthrarufin in G. P. 167,743 and in G. P. 282.49%.

Emmi-p16 8.

11.2 parts by weight of l-hydroxyanthraquinone, 120 parts by weight of nitrobenzene, and 5 parts by weight of sodium carbonate are heated together to a temperature of 1()01l0 Q. and a solution of 8 parts by weightof bromin in 25 parts of nitrobcnzene are gradually introduced. Heating is continued for an hour after the addition of the bromin solution. lllhereatter on cooling the product crystallizes out and can be liltered oil. On recrystallization from glacial acetic acid the product has a melting pointof 190-192 Cj which is the figure quoted in the literature for l-ll V(ll'0X V- l-l)lmntlllthraquinonc.

' [Cm/maple f).

22.4 parts by weight of Q-hydroxyanthraquinone, 10 parts by weight of sodium carbonate. 200 parts by weight of nitrobenzene, and 1 part-by weight of iodin are heated to 130-1 l0 (.l. and chlorin passed in until the required increase in weight for the formation of a Inonchlor derivative is obtained. The product is isolated in the usual way and on recrystallization fromalcohol has a melting point of 226 C. which is that quoted for l-chloro-Elhydroxyanthriupiinone.

()ther neutralizing agents can be employed, c. y. borax or magnesium oxid; sodium acetate is not so good because of the side reaction occurring between the chlorin and the acetate.

Othe' aromatic solvents can be employed c. g. trichlorbenzenc, but nitrobenzene ap-- pears most satisfactor Similar considerations apply in the case of bromination. 7

It has been proposed to chlorinate 1.hydroxyanthraquinone in nitrobenzene suspension by means of sulfuryl chlorin but no suggestion was made to use free chlorin or to add a neutralizing agent.

We declare that what we claim is l. The process of halogenating anthraquinone derivatives in a hot aromatic liquid in presence of a neutralizing agent.

2. The process of halogenat-ing hydroxyanthraquinones in a hot aromatic liquid in presence of a neutralizing agent.

3. The process of chlorinating hydroxyanthraquinones in av hot aroma-tic liquid by the action of free chlorin gas.

l. Th process of halogenating anthraquinone derivatives in hotnitrobenzene in presence of a neutralizing agent.

5. The process of halogenating hydroxyanthraquinones in hot nitrobenzene in presence of a neutralizing agent.

6. The process of chlorinating hydroxyanthraquinones in hot nitrobenzene by the action of free chlorin gas.

7. The process of halogenat ing anthraquinone derivatives in a hot inert aromatic liquid in presence of a neutralizing agent.

8. The process of halogenating hydroxyanthraquinones in a hot inert aromatic liquid in presence of a neutralizing agent.

9. The process of chlorinating hydroxyanthramiinones in a hot inert aromatic liquid by the action of free chlorin gas.

ii). The process of halogenating anthraquinone derivatives in a hot aromatic liquid in presence of a mild alkaline agent.

11. The process of halogenating hydroxyanthraquinone in a hot aromatic. liquid in presence of a mild alkaline agent.

12. The process of halogenating anthraquinone deriva ives in ahot aromatic liquid in prcscnce o't' aneutralizing agent insoluble in, the aromatic liquid.

13. The process of halogenating hydroxyanthraquinones in a hot aromatic liquid in presence of a neutralizing agent insoluble in the aromatic liquid. I

ll. The process of chlorinating anthraquinone derivatives in a hot aromatic liquid in presence of a neutralizing agent by the action of free chlorin gas.

in witness whereof. we have hereunto signed our names this 13th day of May, 1921, in the presence of two subscribing witnesses.

FREDERICK l VILLIAM ATACK.

GEOl-ltllu HOBERTSQN.

l Vitnesscs JoHN l /loLAcnLaN. 

